1. Universität Bayreuth; Lehrstuhl Biochemie und Forschungszentrum für Biomakromoleküle; Universitätsstr. 30 95447 Bayreuth Germany
2. Sapienza University Roma; Department of Drug Chemistry and Technologies and Pasteur Institute of the Cenci-Bolognetti Foundation; P. le A. Moro 5 00185 Rome Italy
3. Department of Medicine; Stanford University School of Medicine; 300 Pasteur Drive Grant Bldg., Rm. S-025 Stanford CA 94305 USA
4. Geriatric Research, Education, and Clinical Center; Department of Veterans Affairs Palo Alto Health Care System; Palo Alto CA 94304 USA
5. Abteilung Enzymology; Institut für Biochemie und Biotechnologie; Martin-Luther-Universität; Kurt-Mothes-Str. 3 06110 Halle (Saale) Germany